Spindle motor and hard disk drive device

ABSTRACT

A spindle motor includes a rotating part, a base member, a connector, and a connector accommodating recess in the base member. The connector accommodating recess includes a bottom surface and an annular wall surface extending from the bottom surface to the outer surface. A through-hole is formed in the bottom surface. The bottom surface includes a first annular surface extending toward the annular wall surface from a peripheral edge of the through-hole, and a second annular surface extending around the first annular surface on an axial outer surface side of the base member relatively to the first annular surface. The connector contacts the second annular surface. A first gap between the connector and the first annular surface is filled with an adhesive. An interface of the adhesive extends i to protrude from an inner peripheral surface of the through-hole over an entire circumference of the through-hole.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application No.2019-155210, filed Aug. 28, 2019, which is hereby incorporated byreference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a spindle motor and a hard disk drivedevice including a spindle motor.

Background

In a hard disk drive devices for driving a hard disk by a spindle motor,a low-density gas such as helium gas having a density lower than that ofair may be enclosed in an internal space of a housing so as to increasethe storage capacity. Such a hard disk drive device is provided with aconnector for electrically connecting components disposed in the harddisk drive device with a circuit board provided outside the hard diskdrive device. Further, in order to prevent leakage of the low-densitygas from a through-hole in a connector accommodating recess formed in abase member forming a housing, a gap between the connector and theconnector accommodating recess is sealed with an adhesive (for example,see Japanese Patent Application Laid-Open No. 2017-120676).

SUMMARY

The base member of the hard disk drive device in which a low-densitygas, such as helium, is enclosed is required to have a high sealingperformance. This is because, if the sealing performance for sealing thegap between the connector accommodating recess of the base member andthe connector with the adhesive is insufficient, the low-density gas,such as helium, leaks from the gap between the connector accommodatingrecess and the connector to the outside of the hard disk drive device.On the other hand, in a case where the connector is accommodated in theconnector accommodating recess, if an uncured adhesive protrudes fromthe gap between an outer peripheral surface of the connector and anannular wall surface of the connector accommodating recess, theprotruding uncured adhesive may adhere to the outside of the base memberduring handling in a manufacturing process.

The present disclosure is related to providing a technique forpreventing an uncured adhesive from protruding and adhering to anoutside of a base member in a manufacturing process, while improving asealing performance for sealing a gap between a connector accommodatingrecess provided in the base member and a connector with an adhesive.

A spindle motor that is applied to a hard disk drive device according toan aspect of the present disclosure includes a rotating part, a basemember, a connector and a connector accommodating recess. The rotatingpart is configured to rotate about a central axis extending in an axialdirection. The base member includes an inner surface and an outersurface, and the base member extends in a radial direction orthogonal tothe axial direction and is configured to support the rotating part on aninner surface side of the base member. A component disposed on the innersurface side of the base member is electrically connected to theconnector. The connector accommodating recess is formed on the outersurface of the base member. The connector accommodating recess includesa bottom surface extending in the radial direction, and an annular wallsurface extending in the axial direction from an outer periphery of thebottom surface to the outer surface. A through-hole is formed in theaxial direction in the bottom surface. The bottom surface includes afirst annular surface extending toward the annular wall surface from aperipheral edge of the through-hole, and a second annular surfacesurrounding the first annular surface. In other words, the secondannular surface extends around the first annular surface to the side ofan outer surface portion extending in the axial direction. The connectorcontacts the second annular surface. A gap between the connector and thefirst annular surface is filled with an adhesive. An interface of theadhesive, when viewed along the axial direction, extends such that theinterface protrudes from an inner peripheral surface of the through-holeover an entire circumference of the through-hole.

A hard disk drive device and a spindle motor according to the presentdisclosure are capable of preventing an uncured adhesive from leakingand adhering to an outside of a base member in a manufacturing process,while improving a sealing performance for sealing a gap between aconnector accommodating recess provided in the base member and aconnector with an adhesive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a hard disk drive device including aspindle motor according to an embodiment of the present disclosure.

FIG. 2 is a plan view of a base member of the hard disk drive deviceillustrated in FIG. 1 as viewed from outside.

FIG. 3 is a partially enlarged plan view of a connector accommodatingrecess of the base member illustrated in FIG. 2.

FIG. 4 is a plan view of a configuration where a connector isaccommodated in the base member illustrated in FIG. 2 as viewed fromoutside.

FIG. 5 is a sectional view taken along a line A-A in FIG. 4.

FIG. 6 is a partially enlarged plan view of a connector accommodatingrecess according to a first modified example of the present disclosure.

FIG. 7 is a sectional view of the connector accommodating recessillustrated in FIG. 6 and a connector.

FIG. 8 is a sectional view of a connector accommodating recess accordingto a second modified example of the present disclosure and a connector.

FIG. 9 is a sectional view of a connector accommodating recess accordingto a third modified example of the present disclosure and a connector.

DETAILED DESCRIPTION

Hereinafter, an embodiment of the present disclosure will be describedwith reference to the drawings.

FIG. 1 is a sectional view illustrating a schematic configuration of ahard disk drive device 1 including a spindle motor 2 according to anembodiment of the present disclosure. Hereinafter, for convenience ofexplanation, a direction along a central axis Y1 of the spindle motor 2illustrated in FIG. 1 is referred to as the axial direction. A side inthe axial direction indicated by the arrow “a” is referred to as theupper side, and a side indicated by the arrow “b” is referred to thelower side. Likewise, a side in the longitudinal direction of the basemember 11 illustrated in FIG. 1 indicated by the arrow “c” is referredto as the right side, and a side indicated by the arrow “d” is referredto as the left side. Further, a side in a lateral direction of the basemember 11 illustrated in FIG. 2 indicated by the arrow “e” is referredto as the front side, and a side indicated by the arrow “f” is referredto as the back side. However, when simply referring to a directionorthogonal to the axial direction, it is referred to as the radialdirection. In the following description, the terms “up”, “down”, “left”,“right”, “front”, and “back”, merely indicate the positionalrelationship and direction in the drawings, and do not indicate thepositional relationship and direction when the members are incorporatedin an actual hard disk drive device.

The spindle motor 2 for the hard disk drive device 1 according to theembodiment of the present disclosure includes a rotor part 30 serving asa rotating part that rotates about the central axis Y1 extending in theaxial direction, a base member 11 that extends in the radial directionorthogonal to the axial direction, a connector 40 to which a componentdisposed on the inner surface 11 a side of the base member 11 iselectrically connected, and a connector accommodating recess 50. Thebase member 11 includes an inner surface 11 a and an outer surface 11 b,and supports the rotor part 30 on an inner surface 11 a side. Theconnector accommodating recess 50 is formed on the outer surface 11 b ofthe base member 11 to accommodate the connector 40. The connectoraccommodating recess 50 is recessed toward the inner surface 11 a sideof the base member 11 and includes a bottom surface 51 extending in theradial direction and an annular wall surface 52 extending in the axialdirection from the outer periphery of the bottom surface 51 toward theouter surface 11 b. The bottom surface 51 is provided with athrough-hole 53 that passes through the base member 11 in the axialdirection.

The bottom surface 51 of the connector accommodating recess 50 includesa first annular surface 55 that extends from a peripheral edge 53 a ofthe through-hole 53 toward the annular wall surface 52, and a secondannular surface 57 that surrounds the first annular surface 55. Thefirst annular surface 55 is recessed with respect to the second annularsurface 57. Accordingly, while the connector 40 contacts the secondannular surface 57, a gap G is formed between the connector 40 and thefirst annular surface 55. The gap G is sealed by filling the gap G withan adhesive AD. When viewed along the axial direction, an interface ofthe cured adhesive AD extends in such a manner that the interface of thecured adhesive AD protrudes from the inner peripheral surface 53 b ofthe through-hole 53 over the entire circumference, i.e. the entireperipheral edge 53 a of the through-hole 53. On the other hand, theadhesive AD is not present in a gap between a connector outer peripheralsurface 41 of the connector 40 and the annular wall surface 52 of theconnector accommodating recess 50. Hereinafter, the configuration of thehard disk drive device 1 will be described in detail.

As illustrated in FIG. 1, in the hard disk drive device 1, a cover 3 isjoined to the upper side of the base member 11 that accommodatescomponents of the spindle motor 2 for sealing the inside of the basemember 11 and creating a clean internal space S with an extremely smallamount of dust, dirt, or the like. The base member 11 and the cover 3are hermetically sealed by a sealing member such as an elastomer, anadhesive, welding, or the like, thereby forming a housing for the harddisk drive device 1.

The internal space S formed by the base member 11 and the cover 3 isfilled with a low-density gas having a density lower than that of air.Examples of the low-density gas include helium, nitrogen, and a gasmixture of helium and nitrogen. The spindle motor 2 is, for example,attached with eight hard disks 4. However, in FIG. 1, the illustrationof some of the hard disks is omitted. The use of a gas with a densitylower than that of air provides reductions of resistance applied to thehard disk 4, vibration of the hard disks 4 during rotation and powerconsumption of the spindle motor 2.

The hard disks 4 are attached coaxially with the central axis Y1 of thespindle motor 2. The hard disks 4 are fixed to the spindle motor 2 byfixing a clamp member with mounting screws screwed into screw holesprovided on the upper side of a rotor member 31 of the spindle motor 2.Thus, the hard disks 4 rotate integrally with the spindle motor 2.According to the embodiment of the present disclosure, eight hard disks4 are attached to the spindle motor 2. However, the number of hard disks4 is not limited to eight.

Further, the hard disk drive device 1 includes a head part 5 including amagnetic head that executes writing and reading of information on thehard disk 4, an arm 6 that supports the head part 5, and a head actuatormechanism 7 that moves the head part 5 and the arm 6 to predeterminedpositions. The head actuator mechanism 7 is fixed to a predeterminedposition on the inner surface 11 a of the base member 11, and the arm 6is swingably supported by the head actuator mechanism 7. The head part 5is disposed such that, for example, each of the hard disks 4 issandwiched to perform writing and reading of information on both sidesof each hard disk 4.

The connector accommodating recess 50 is formed at a predeterminedposition of the base member 11. The connector 40 for connecting anexternal control board (not illustrated) is accommodated in theconnector accommodating recess 50. The connector 40 and a connectionportion 8 of the head actuator mechanism 7, which is a componentdisposed on the inner surface 11 a side of the base member 11, areelectrically connected via the through-hole 53 in the connectoraccommodating recess 50. Specific configurations of the connector 40 andthe connector accommodating recess 50 will be described below.

The control information of the head actuator mechanism 7 is transmittedto the head actuator mechanism 7 from the control board through theconnector 40 and the connection portion 8 of the head actuator mechanism7, and as a result the arm 6 swings. Further, information read out fromeach hard disk 4 by the head part 5 is transmitted to the control boardthrough the connection portion 8 of the head actuator mechanism 7 andthe connector 40. Reversely, information to be written on each hard disk4 is transmitted from the control board to the head part 5 through theconnector 40 and the connection portion 8 of the head actuator mechanism7.

The spindle motor 2 includes a stator part 10, a fluid dynamic pressurebearing 20, and a rotor part 30. The stator part 10 includes the basemember 11 and a stator core 12 that is fixed to the base member 11.

The base member 11 is formed of, for example, an aluminum alloy, andincludes the inner surface 11 a, which is the upper (inner) surfacewhere the stator core 12 is fixed, and the outer surface 11 b, which isthe lower (outer) surface axially opposite to the inner surface 11 a.The base member 11 defines the internal space S of the hard disk drivedevice 1 with the cover 3, which covers the base member 11.

In the base member 11, a shaft insertion hole 11 c through which a lowerend portion of a shaft member 21 is inserted and fixed, and acircumferential wall part 11 d that is coaxial with the shaft insertionhole 11 c are formed. Further, the stator core 12 is fixed to the outerperipheral surface of the circumferential wall part 11 d, and coils 13are wound around the stator core 12.

The lead wire 14 is drawn out from the coil 13. The lead wire 14 isconnected to a flexible printed circuit board (FPC) 15, which isattached to the outer surface 11 b of the base member 11, by soldering.Control signal of the spindle motor 2 is supplied to the coil 13 throughthe lead wire 14 from an output end of the flexible printed circuitboard 15.

The fluid dynamic pressure bearing 20 includes the shaft member 21inserted to an upper conical bearing member 22 and a lower conicalbearing member 23. The upper conical bearing member 22 and the lowerconical bearing member 23 are fixed to the shaft member 21 spacing apartfrom each other in the axial direction. The shaft member 21 is disposedcoaxially with the central axis Y1. A screw hole extending axially isformed from an upper end surface of the shaft member 21. A fixationscrew is screwed into this screw hole, thereby fixing the cover 3 to theshaft member 21.

The lower end portion of the shaft member 21 is inserted into the shaftinsertion hole 11 c, which is formed in the base member 11 coaxial withthe central axis Y1. The shaft member 21 is fixed by press fitting or bybonding and press fitting. Thus, the shaft member 21 is also coaxialwith the central axis Y1. Further, the shaft member 21 is inserted intoa shaft hole 31 a, which is formed in the rotor member 31 of the rotorpart 30. As a result, the rotor part 30 can rotate about the centralaxis Y1 through the fluid dynamic pressure bearing 20.

The rotor part 30 includes the rotor member 31, a yoke 32, a rotormagnet 33, and an end cap 34. The rotor member 31 is formed in asubstantially cup shape. Further, a yoke attaching portion 31 c and theshaft hole 31 a, to which the shaft member 21 is inserted, are formed inthe rotor member 31. The rotor magnet 33 is fixed to the yoke attachingportion 31 c via the yoke 32. The rotor magnet 33 is formed of apermanent magnet and is disposed facing the stator core 12.

The rotor member 31 includes upper and lower conical inner surfaces 31 brespectively at the upper end portion and the lower end portion of theshaft hole 31 a. The upper and lower conical inner surfaces 31 b facerespectively an upper conical outer surface 22 a of the upper conicalbearing member 22 and a lower conical outer surface 23 a of the lowerconical bearing member 23 via minute gaps. The inner diameter of theconical inner surface 31 b that faces the upper conical outer surface 22a increases toward the upper side of the shaft hole 31 a of the rotormember 31. The inner diameter of the conical inner surface 31 b thatfaces the lower conical outer surface 23 a increases toward the lowerside of the shaft hole 31 a of the rotor member 31. The minute gapbetween the conical inner surface 31 b and the upper conical outersurface 22 a and the minute gap between the conical inner surface 31 band the lower conical outer surface 23 a are filled with lubricant oil(not illustrated).

Each of the upper and lower conical inner surfaces 31 b includes adynamic pressure groove portion (not illustrated) where dynamic pressuregrooves are formed by electrochemical machining. When the rotor part 30is rotated, the upper and lower dynamic pressure groove portionsgenerate a dynamic pressure in the lubricant oil filling the minute gapsbetween the upper and lower conical inner surfaces 31 b and the upperand lower conical outer surfaces 22 a, 23 a by the action of the dynamicpressure groove, thereby supporting the rotor part 30 in a non-contactmanner. The dynamic pressure groove may be formed on each of the upperconical outer surface 22 a and the lower conical outer surface 23 ainstead of the upper and lower conical inner surfaces 31 b.

A taper seal portion having a gap width that increases toward theoutside is formed continuous to an upper end of the minute gap betweenthe upper dynamic pressure groove portion and the upper conical outersurface 22 a. The meniscus of the lubricant oil is located in the taperseal portion. Also, at a lower end of the minute gap between the lowerdynamic pressure groove portion and the lower conical outer surface 23a, a taper seal portion similar to that described above is formed andthe meniscus of the lubricant oil is located in the taper seal portion.A capillary force acting in the taper seal portions prevents leakage ofthe lubricant oil.

Further, the rotor member 31 is provided with the end cap 34. The endcap 34 is a member for covering the opening in the taper seal portion toprevent leakage of the lubricant oil. The end cap 34 is fixed to therotor member 31 by bonding or by bonding and press fitting. A small gapis formed between the end cap 34 and the shaft member 21 so as toprevent the end cap 34 from disturbing the rotation of the rotor member31.

The rotor magnet 33 fixed to the rotor part 30 and the stator core 12fixed to the base member 11 face each other through the small gap. Whendrive currents having different phases flow through the plurality ofcoils 13 wound around the stator core 12, a rotating magnetic field isgenerated and a rotating torque is generated on the rotor magnet 33.This allows the rotor part 30 to rotate around the stator part 10 viathe fluid dynamic pressure bearing 20.

When the rotor part 30 is rotated via the fluid dynamic pressure bearing20, a dynamic pressure causing the separation of the upper conical innersurface 31 b of the rotor part 30 and the upper conical outer surface 22a, and the separation of the lower conical inner surfaces 31 b of therotor part 30 and the lower conical outer surface 23 a is generated bythe dynamic pressure grooves provided in the dynamic pressure grooveportions. With this configuration, the conical inner surfaces 31 b andeach of the upper conical outer surface 22 a and the lower conical outersurface 23 a are brought into a non-contact state. Further, when theconical inner surfaces 31 b and each of the conical outer surfaces 22 aand 23 a is brought into a non-contact state, the rotor part 30 rotatesaround the stator part 10 in a non-contact state.

FIG. 2 is a plan view of the base member 11 of the hard disk drivedevice 1 illustrated in FIG. 1 as viewed from the outside (lower side)of the hard disk drive device 1. FIG. 3 is a partially enlarged planview of the connector accommodating recess 50 of the base member 11illustrated in FIG. 2. FIG. 4 is a plan view of a configuration in whichthe connector 40 is attached in the base member 11 illustrated in FIG. 2as viewed from the outside. FIG. 5 is a sectional view taken along aline A-A in FIG. 4.

As illustrated in FIGS. 2 and 3, the connector accommodating recess 50is provided on the outer surface (lower surface) 11 b of the base member11, and is recessed toward the inner surface (upper surface) 11 a. Theconnector accommodating recess 50 includes the bottom surface 51 and theannular wall surface 52 that is an annular surface that surrounds thebottom surface 51 and extends downward from a peripheral edge 51 a tothe outer surface 11 b. In the bottom surface 51, the through-hole 53that passes through the base member 11 in the axial direction is formed.The bottom surface 51 includes the first annular surface 55 that extendsin the radial direction from the peripheral edge 53 a of thethrough-hole 53, and the second annular surface 57 that surrounds thefirst annular surface 55 and extends to the annular wall surface 52. Asillustrated in FIG. 5, the first annular surface 55 is located on theupper side of the second annular surface 57, and thus the first annularsurface 55 is recessed with respect to the second annular surface 57,thereby forming a step portion 54.

The connector accommodating recess 50 is formed on the left side and thefront side in the outer surface 11 b of the base member 11. Theconnector accommodating recess 50 is formed in a shape corresponding tothe connector 40, and is formed, for example, in a rectangular shape ina plan view. The bottom surface 51 of the connector accommodating recess50 extends in a rectangular shape in a plan view, and the peripheraledge 51 a on the outer periphery side of the bottom surface 51 isconnected to an upper end of the annular wall surface 52 of theconnector accommodating recess 50.

The annular wall surface 52 of the connector accommodating recess 50extends in a rectangular tubular shape on the lower side along the axialdirection from the peripheral edge 51 a on the outer periphery side ofthe bottom surface 51, and a lower end of the annular wall surface 52 isconnected to the outer surface 11 b of the base member 11.

The through-hole 53 passes through the base member 11 in the axialdirection, and is formed, for example, in a central portion of thebottom surface 51. The through-hole 53 of the connector accommodatingrecess 50 is formed corresponding to the connection portion 8 of thehead actuator mechanism 7. For example, the dimensions of thethrough-hole 53 in the lateral direction of the base member 11 aregreater than the dimensions of the through-hole 53 in the longitudinaldirection of the base member 11. The through-hole 53 is a connectorwindow for inserting the connection portion 8 of the head actuatormechanism 7 and connecting the connection portion 8 to the connector 40.

Further, in the bottom surface 51, the step portion 54 is formedsurrounding the lower peripheral edge 53 a of the through-hole 53. Inthe step portion 54, the first annular surface 55 extends in such amanner that the first annular surface 55 spreads in the radial directionfrom the lower peripheral edge 53 a of the through-hole 53. The firstannular surface 55 is a part of the bottom surface 51 of the connectoraccommodating recess 50, and extends annularly whose inner peripheraledge is the peripheral edge 53 a of the through-hole 53 in the connectoraccommodating recess 50. The dimension of the first annular surface 55in the lateral direction of the base member 11 are greater than thedimension of the first annular surface 55 in the longitudinal directionof the base member 11.

Further, the step portion 54 includes a step portion annular wallsurface 56 that is an annular surface extending downward along the axialdirection from an outer peripheral edge 55 a of the first annularsurface 55. The length of the step portion annular wall surface 56 inthe axial direction is shorter than the length of the annular wallsurface 52 in the axial direction (FIG. 5). A lower peripheral edge 56 aof the step portion annular wall surface 56 is connected to the secondannular surface 57 that defines a part of the bottom surface 51 of theconnector accommodating recess 50.

The second annular surface 57 extends in such a manner that the secondannular surface 57 spreads in the radial direction from the lowerperipheral edge 56 a of the step portion annular wall surface 56. Thesecond annular surface 57 extends, for example, in a rectangular annularshape with the lower peripheral edge 56 a of the step portion annularwall surface 56 being an inner peripheral edge and with the peripheraledge 51 a on the outer periphery side of the bottom surface 51 of theconnector accommodating recess 50 being an outer peripheral edge. Thedimension of the second annular surface 57 in the lateral direction ofthe base member 11 is longer than the dimension of the second annularsurface 57 in the longitudinal direction of the base member 11.

As illustrated in FIG. 5, the connector 40 contacts the second annularsurface 57 whereas the gap G is formed between the connector 40 and thefirst annular surface 55. The gap G is filled with the adhesive AD. Theinterface of the adhesive AD is exposed by protruding in the radialdirection from the inner peripheral surface 53 b of the through-hole 53over the entire length of the peripheral edge 53 a of the through-hole53. However, the adhesive AD is not present in the gap between theconnector outer peripheral surface 41 and the annular wall surface 52 ofthe connector accommodating recess 50.

The connector 40 is formed, for example, in a rectangular shape in aplan view. As illustrated in FIG. 5, the connector 40 includes aconnector inner surface 40 a that is an upper (inner side) surface, aconnector outer surface 40 b that is a lower (outer side) surfaceopposite to the connector inner surface 40 a, and the connector outerperipheral surface 41 that connects the connector inner surface 40 a andthe connector outer surface 40 b to each other. As illustrated in FIG.1, the connector 40 is electrically connected to the connection portion8 of the head actuator mechanism 7 by respectively connecting aplurality of terminals (not illustrated) of the connector inner surface40 a to a plurality of terminals of the connection portion 8 of the headactuator mechanism 7.

The longitudinal and the lateral lengths of the connector 40 arerespectively shorter than the longitudinal and the lateral lengths ofthe connector accommodating recess 50. Further, the axial length of theconnector 40 is shorter than the axial length of the annular wallsurface 52 of the connector accommodating recess 50. With thisconfiguration, the connector 40 can be accommodated in the connectoraccommodating recess 50.

As illustrated in FIG. 5, in the connector 40, a part of the connectorinner surface 40 a next to the connector outer peripheral surface 41contacts the second annular surface 57, and a part of the connectorinner surface 40 a that is closer to the center than the contacting partfaces the first annular surface 55. Further, a central portion of theconnector inner surface 40 a faces the through-hole 53. The gap G isformed in the axial direction around the entire periphery of thethrough-hole 53 between the first annular surface 55 and the part of theconnector inner surface 40 a that is closer to the center of theconnector inner surface 40 a. Further, the connector 40 is accommodatedin the central portion of the connector accommodating recess 50, and theconnector outer peripheral surface 41 does not contact the annular wallsurface 52 of the connector accommodating recess 50.

The adhesive AD fills the gap G between the first annular surface 55 andthe connector inner surface 40 a over the whole periphery of the firstannular surface 55. Further, the interface of the adhesive AD extendssuch that the interface distances from an imaginary surface extendedfrom the inner peripheral surface 53 b of the through-hole 53, towardthe inside of the connector accommodating recess 50 as the interfaceapproaches to the connector inner surface 40 a from the first annularsurface 55 in the axial direction. In other words, when the connector 40is viewed along the axial direction from a position on the inner surface11 a side of the base member 11, the interface of the adhesive AD thatis exposed protruding from the inner peripheral surface 53 b of thethrough-hole 53 along the connector inner surface 40 a is visible. Thus,since the formation of the interface of the adhesive AD over the entireperiphery of the through-hole 53 can be verified by visual observation,it is possible to easily confirm that the gap between the connectoraccommodating recess 50 and the connector 40 is reliably sealed.

Further, the adhesive AD is not present in the gap between the connectorouter peripheral surface 41 and the annular wall surface 52 of theconnector accommodating recess 50, which is the gap leading to the outersurface 11 b of the base member 11. In other words, since the gap G andthe step portion annular wall surface 56 are provided between theconnector inner surface 40 a and the bottom surface 51 of the connectoraccommodating recess 50, the adhesive AD is blocked by the step portionannular wall surface 56 and the adhesive AD is retained in the gap Gwhen the gap between the connector 40 and the connector accommodatingrecess 50 is sealed. Therefore, it is also easy to adjust the coatingamount of the adhesive AD to prevent leakage of the adhesive AD into thegap between the connector outer peripheral surface 41 and the annularwall surface 52 of the connector accommodating recess 50. Consequently,it is possible to prevent the uncured adhesive AD from adhering to theouter side of the base member 11 during handling in a manufacturingprocess when the connector 40 is bonded to the connector accommodatingrecess 50. Further, an adhesive layer with a thickness corresponding tothe gap width of the gap G is formed and thus a satisfactory sealingperformance can be obtained. The thickness of the adhesive layer forobtaining the satisfactory sealing performance can be easily adjusted bychanging the axial length of the step portion annular wall surface 56.

The adhesive AD is required to be easily cured in the gap G in which airis blocked and to have low outgas property. Accordingly, it ispreferable to use a thermosetting epoxy-based adhesive as the adhesiveAD. However, an acrylic adhesive that is anaerobic and ultravioletcurable may also be used as the adhesive AD.

As described above, in the hard disk drive device 1 according to theembodiment of the present disclosure, the gap G is formed between theconnector 40 and the first annular surface 55, and the gap G is sealedwith the adhesive AD. The interface of the adhesive AD extends such thatthe interface protrudes in the radial direction from the innerperipheral surface 53 b over the entire periphery of the through-hole53, and the adhesive AD is not present in the gap between the connectorouter peripheral surface 41 and the annular wall surface 52 of theconnector accommodating recess 50.

Since the interface of the adhesive AD is formed over the wholeperiphery of the through-hole 53, the sealing performance between theconnector accommodating recess 50 and the connector 40 can be improved.Further, since the interface of the adhesive AD can be viewed from theinner surface 11 a side of the base member 11, it can easily confirmthat the improved sealing performance between the connectoraccommodating recess 50 and the connector 40 is obtained. Further, whenthe connector 40 is accommodated in the connector accommodating recess50, the adhesive AD does not spread to the gap between the connectorouter peripheral surface 41 and the annular wall surface 52 of theconnector accommodating recess 50, thereby preventing the uncuredadhesive AD from adhering to the outer side of the base member 11 duringhandling.

While an embodiment of the present disclosure has been described above,the present disclosure is not limited to the above-described embodiment.A variety of modes included in the concept of the present disclosure andthe scope of claims are also included in the present disclosure.Further, the components can be appropriately selected and combined toobtain at least some of the above-described advantageous effects.

For example, as a first modified example of the hard disk drive device 1according to the embodiment of the present disclosure, as illustrated inFIGS. 6 and 7, an annular groove 60 that is recessed toward the innerside from the outer side of the base member 11 between the annular wallsurface 52 and the second annular surface 57 of the connectoraccommodating recess 50 may be further provided.

In this case, as illustrated in FIG. 7, the annular groove 60 includesan annular groove bottom surface 61, an outer peripheral wall 62 thatextends toward the lower side in the axial direction from the peripheraledge on the outer periphery side of the groove bottom surface 61, and aninner peripheral wall 63 that extends toward the lower side in the axialdirection from the peripheral edge on the inner periphery side of thegroove bottom surface 61. The lower peripheral edge of the innerperipheral wall 63 is connected to the second annular surface 57, andthe outer peripheral wall 62 is flush with the annular wall surface 52of the connector accommodating recess 50. In other words, the outerperipheral wall 62 of the annular groove 60 forms a part of the annularwall surface 52 of the connector accommodating recess 50.

Further, the annular groove 60 has a depth greater than the axialdimension of the gap G. In other words, the axial length of the innerperipheral wall 63 is longer than the axial length of the step portionannular wall surface 56 of the step portion 54. Further, the outerperipheral portion of the connector inner surface 40 a faces the groovebottom surface 61 of the annular groove 60.

For this reason, even when the amount of the adhesive AD is excessive,the uncured adhesive AD leaking from the gap G is retained in theannular groove 60, thereby preventing the adhesive AD from spreading tothe gap between the connector outer peripheral surface 41 and theannular wall surface 52 of the connector accommodating recess 50.Consequently, it is possible to prevent the uncured adhesive AD fromadhering to the outer side of the base member 11 during handling in amanufacturing process.

Further, the present disclosure is not limited to the first modifiedexample. Like in a second modified example illustrated in FIG. 8, theannular groove 60 may be formed in the second annular surface 57separated from the annular wall surface 52. In this case, the outerperipheral wall 62 of the annular groove 60 is not flush with theannular wall surface 52 of the connector accommodating recess 50.Therefore, the outer peripheral wall 62 is not continuous with theannular wall surface 52 of the connector accommodating recess 50.

Further, in a third modified example of the hard disk drive device 1according to the embodiment of the present disclosure, as illustrated inFIG. 9, a metal coating 64 such as electroless nickel plating may beformed on the connector inner surface 40 a. With this configuration, thewettability of the connector inner surface 40 a to the adhesive AD canbe improved and the interface of the adhesive AD is more easily formedon the connector inner surface 40 a at the inside of the imaginarysurface extended from the inner peripheral surface 53 b. Consequently,the sealing performance between the connector accommodating recess 50and the connector 40 can be further improved.

What is claimed is:
 1. A spindle motor comprising: a rotating partconfigured to rotate about a central axis extending in an axialdirection; a base member including an inner surface and an outersurface, the base member extending in a radial direction orthogonal tothe axial direction and being configured to support the rotating part onan inner surface side; a connector to which a component disposed on theinner surface side of the base member is electrically connected; and aconnector accommodating recess formed on the outer surface of the basemember, wherein the connector accommodating recess includes a bottomsurface extending in the radial direction, and an annular wall surfaceextending in the axial direction from an outer periphery of the bottomsurface to the outer surface, a through-hole is formed in the axialdirection in the bottom surface, the bottom surface includes a firstannular surface extending toward the annular wall surface from aperipheral edge of the through-hole, and a second annular surfacesurrounding the first annular surface, the connector contacts the secondannular surface, a first gap between the connector and the first annularsurface is filled with an adhesive, and an interface of the adhesive,when viewed along the axial direction, extends protruding from an innerperipheral surface of the through-hole over an entire circumference ofthe through-hole.
 2. The spindle motor according to claim 1, wherein theadhesive is not present in a second gap between an outer peripheralsurface of the connector and the annular wall surface of the connectoraccommodating recess.
 3. The spindle motor according to claim 1, furthercomprising an annular groove that is recessed toward the inner surfaceof the base member and located between the annular wall surface of theconnector accommodating recess and the second annular surface or on thesecond annular surface.
 4. The spindle motor according to claim 3,wherein a depth of the annular groove is greater than an axial dimensionof the first gap.
 5. The spindle motor according to claim 3, wherein anouter peripheral wall surface of the annular groove is flush with theannular wall surface of the connector accommodating recess.
 6. Thespindle motor according to claim 1, wherein a metal coating is formed ona surface of the connector, the surface being in contact with the secondannular surface.
 7. A hard disk drive device comprising: the spindlemotor according to claim 1; a cover member configured to form a sealedinner space with the base member; a gas with a density lower than adensity of air filling the inner space; a hard disk to be rotated by themotor part; and a head part configured to at least read information fromthe hard disk or write information to the hard disk.
 8. The spindlemotor according to claim 1, wherein the interface of the adhesive isvisible when viewed along the axial direction.
 9. The spindle motoraccording to claim 2, wherein the interface of the adhesive is visiblewhen viewed along the axial direction.
 10. The spindle motor accordingto claim 9 further comprising an annular groove that is recessed towardthe inner surface of the base member and located between the annularwall surface of the connector accommodating recess and the secondannular surface or on the second annular surface.
 11. The spindle motoraccording to claim 10, wherein a depth of the annular groove is greaterthan an axial dimension of the first gap.
 12. The spindle motoraccording to claim 11, wherein an outer peripheral wall surface of theannular groove is flush with the annular wall surface of the connectoraccommodating recess.
 13. The spindle motor according to claim 3,wherein an outer peripheral wall surface of the annular groove isseparated from the annular wall surface of the connector accommodatingrecess.
 14. The spindle motor according to claim 11, wherein an outerperipheral wall surface of the annular groove is separated from theannular wall surface of the connector accommodating recess.
 15. Thespindle motor according to claim 9, wherein a metal coating is formed ona surface of the connector, the surface being in contact with the secondannular surface.
 16. The spindle motor according to claim 10, wherein ametal coating is formed on a surface of the connector, the surface beingin contact with the second annular surface.
 17. A hard disk drive devicecomprising: the spindle motor according to claim 9; a cover memberconfigured to form a sealed inner space with the base member; a gas witha density lower than a density of air filling the inner space; a harddisk to be rotated by the motor part; and a head part configured to atleast read information from the hard disk or write information to thehard disk.
 18. A hard disk drive device comprising: the spindle motoraccording to claim 10; a cover member configured to form a sealed innerspace with the base member; a gas with a density lower than a density ofair filling the inner space; a hard disk to be rotated by the motorpart; and a head part configured to at least read information from thehard disk or write information to the hard disk.